JP2003262550A - Protective tube type thermocouple for microwave high temperature oven and thermocouple mounting structure in microwave high temperature oven - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a protective tube type thermocouple for microwave high temperature ovens and a thermocouple mounting structure in the microwave high temperature oven which is capable of more accurately and very cheaply measuring the temperature of an object such as sintered materials, without leaking a microwave out of the microwave high temperature oven. <P>SOLUTION: The protective tube type thermocouple 1 for microwave high temperature ovens has a sensor 2 having a thermocouple and a protective tube 3 hermetically sealing and covering the sensor 2. The tube 3 is made of a microwave-impermeable material having a heat resistance of at least 1000°C and not permitting the transmission of microwaves. A mount 6 for mounting in a housing of the high temperature microwave oven is attached to a conductive part 5 formed on the root end of the pipe 3. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protective tube type thermocouple suitable for use in a microwave high temperature furnace and a thermocouple mounting structure in the microwave high temperature furnace.

[0002]

2. Description of the Related Art Conventionally, a radiation thermometer has been mainly used as a measuring means for measuring the surface temperature of a fired body fired in a microwave high temperature furnace or the temperature in the firing chamber. This radiation thermometer is suitable for temperature measurement in a microwave high temperature furnace because it can measure from outside the firing furnace and can measure temperature without leaking microwaves to the outside of the furnace.

[0003]

The radiation thermometer, however, measures the temperature by detecting the radiant energy of the measuring object, and requires a variety of devices to decode the detected signal, which is extremely expensive. In addition, if the measurement points are not set or the emissivity is not properly corrected, an error will increase and accurate temperature measurement will be difficult.

On the other hand, thermocouples are used for temperature measurement in general firing furnaces, and some of these thermocouples are also applicable to high temperature measurement exceeding 2000 ° C. and are inexpensive. However, this thermocouple must have a heat contact near the object to be measured in the furnace, which causes microwave leakage in the microwave high temperature furnace.

Therefore, an object of the present invention is to provide a protective tube type thermocouple for a microwave high temperature furnace, which can measure the temperature of the fired body more accurately and extremely inexpensively without the microwave leaking out of the microwave high temperature furnace. It is to provide a thermocouple mounting structure in a microwave high temperature furnace.

[0006]

[Means for Solving the Problems] A solution to the above problems is to provide a sensor section having a thermocouple, a sensor section covered in a hermetically sealed state, and a heat resistance capable of withstanding at least 1000 ° C., and It has a protective tube formed of a microwave impermeable material that does not allow the transmission of microwaves,
A high-temperature microwave oven characterized in that a conductive portion is formed at a base end side portion of the protection tube, and a mounting member for mounting the housing on the microwave high-temperature furnace is attached to the conductive portion. It is a protective tube type thermocouple for furnaces.

[0007] Further, what solves the above-mentioned problems is to provide a sensor part having a thermocouple, a sensor part covered in a hermetically sealed state, a heat resistance capable of withstanding at least 1000 ° C, and a microwave transmission. And a protective tube made of a microwave impermeable material that does not allow the conductive tube, a conductive portion is formed at a base end side portion of the protective tube, and the conductive portion is mounted in a microwave high temperature furnace. A protective tube type thermocouple to which a mounting member for mounting is attached to a microwave high temperature furnace, and the distal end of the protective tube is arranged so as to be located in the vicinity of a measurement target, and the mounting is performed. A thermocouple mounting structure in a microwave high-temperature furnace, characterized in that the structure is attached to a housing of the microwave high-temperature furnace by a member for use.

The protective tube type thermocouple for a microwave high temperature furnace according to the present invention is formed of a microwave impermeable material which has heat resistance such that the protective tube can withstand at least 1000 ° C. and does not allow transmission of microwaves. Therefore, the microwave does not enter the protective tube and leak out of the furnace. Further, a conductive portion is formed at the base end side portion of the protective tube, and a mounting member for mounting on the housing of the microwave high-temperature furnace is attached to the conductive portion, so that it is transmitted on the surface of the protective tube. The microwave is grounded and never leaks out of the furnace. As described above, since the protection tube type thermocouple for the microwave high temperature furnace of the present invention is designed so that microwaves do not leak out of the furnace through the protection tube type thermocouple, the microwave high temperature furnace The temperature of the measurement target (for example, the firing chamber) can be measured accurately and very inexpensively.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION A protective tube type thermocouple for a microwave high temperature furnace according to the present invention will be described with reference to an embodiment shown in FIG.
1 is a side view of an embodiment of a protective tube type thermocouple for a microwave high temperature furnace according to the present invention.

As shown in FIG. 1, a protective tube type thermocouple 1 for a microwave high temperature furnace according to the present invention covers a sensor portion 2 having a thermocouple and a sensor portion 2 in a hermetically sealed state, and at least 1000 The protective tube 3 is formed of a microwave impermeable material that has heat resistance capable of withstanding ° C, and does not allow transmission of microwaves, and a terminal box 4 provided at the proximal end of the protective tube 3. A conductive portion 5 is formed at a base end side portion of the protective tube 3, and a mounting member 6 for mounting on the housing of the microwave high temperature furnace is attached to the conductive portion 5. Hereinafter, each configuration will be sequentially described in detail.

The sensor section 2 is for measuring the temperature of the object to be measured, and is constructed by arranging a thermocouple (not shown) in a protective tube 3 described later. As the thermocouple, one having heat resistance capable of withstanding at least 1000 ° C. or higher, for example, platinum / rhodium, iridium / rhodium, or the like can be preferably used.

The protective tube (sheath) 3 is for preventing the microwave from entering the tube and for preventing the microwave from leaking to the outside through the protective tube type thermocouple. Is hermetically sealed.

Specifically, the protective tube 3 is integrally molded into a tubular body whose front end (the left end of the protective tube 3 in FIG. 1) is sealed, and the proximal end of the tubular body has a terminal box described later. 4 is attached. In addition, a thermocouple and a lead wire (not shown) connected to the thermocouple are arranged in the tubular body,
This conducting wire is electrically connected to the terminals 4a and 4b.

The protective tube 3 of the protective tube type thermocouple 1 for microwave high-temperature furnace of the present invention has heat resistance capable of withstanding at least 1000 ° C. (more preferably 1400 ° C. to 1500 ° C.) and has a microwave resistance. It is made of a microwave impermeable material that does not allow transmission. As a result, the microwave can be used in the microwave high-temperature furnace, and the microwave enters the protective tube 3 of the protective tube type thermocouple 1 for the microwave high-temperature furnace, and the microwave enters the outside of the furnace through the inside of the protective tube 3. Can be prevented from leaking.

The protective tube 3 may be made of any material as long as it has heat resistance capable of withstanding at least 1000 ° C. and does not allow transmission of microwaves. The protective tube 3 is formed of a dense cermet material made of molybdenum disilicide and a glassy oxide.

The term "material that does not allow the transmission of microwaves" as used herein means, in addition to materials that block microwaves,
Materials that reflect microwaves, such as metals, are also included. Further, although the protective tube 3 of this embodiment is integrally formed of glassy oxide containing molybdenum disilicide, the present invention is not limited to this, and may be silicon carbide or silicon nitride, for example.

The conductive portion 5 prevents the surface of the protective tube 3 from being oxidized and insulated, and prevents microwaves from leaking through the portion or generating an arc with the housing of the microwave high temperature furnace. And is provided at the base end side portion of the protective tube 3.

More specifically, the protective tube 3 of this embodiment
Does not oxidize because it forms an oxidation resistant film of quartz glass at high temperatures, but it oxidizes and insulates at the base end side portion (low temperature region). When a mounting member 6 to be described later is attached to this insulated portion, microwaves may be transmitted to the insulated portion and leak to the outside, and an arc is generated between the insulated portion and the housing. To do. Therefore, the formation of the conductive portion 5 prevents the surface of the protective tube 3 from being oxidized, and the housing 11 of the microwave high temperature furnace 1 and the protective tube 3 are brought into contact with each other via the conductive portion 5 to be grounded.

The conductive portion may have any structure as long as it is formed so that the surface of the base end side portion of the protective tube has conductivity. However, the conductive portion 5 of this embodiment is not limited thereto.
Is formed by attaching and coating a conductive material on the surface of the base end portion of the protective tube 3.

Any material may be used as the conductive material for forming the conductive portion 5, but alumina, copper, aluminum, gold, silver, platinum or the like can be preferably used.

A mounting member 6 for mounting the microwave protection tube type thermocouple 1 for the microwave high temperature furnace 10 on the housing 11 of the microwave high temperature furnace 10 is attached to the conductive portion 5. As shown in FIG. 3, the mounting member 6 of this embodiment is formed of a tubular member fitted and fixed to the conductive portion 5, and has a threaded portion 18a of a protective tube type thermocouple mounting member 18, which will be described later, on its surface.
Has a threaded portion 6a for engaging with.

More specifically, the mounting member 6 of this embodiment is, as shown in FIG. 4, from one side of the conductive ring 8 fitted to the conductive portion 5 (the tip side of the protective tube 3). It is fitted to the conductive ring 8 so that its inner surface is in contact, and for fitting with the threaded portion 7a of the fixing member 7 fitted from the other side of the conductive ring 8 (the proximal end side of the protective tube 3). The structure is such that the second screwing portion 6b provided on the inner surface of the member 6 engages and is attached to the conductive portion 5. Then, such a conductive ring 8 is clamped from both sides by the mounting member 6 and the fixing member 7 and the mounting member 6 is mounted on the conductive portion 5, so that the arc is generated more reliably. Not only can it be prevented, but leakage of microwaves can also be prevented more reliably.

The conductive ring 8 of this embodiment is made of copper, but is not limited to this, and may be made of any conductive material. Further, this conductive ring is slidably attached along the protection tube, and thereby the insertion degree of the protection tube can be adjusted according to the measurement site.

The terminal box 4 includes terminals 4a, which are electrically connected to the thermocouple,
4b, which is attached to the base end of the protective tube 3. Then, the terminals 4a and 4b are configured to be connectable via a conductor 21 to a measuring instrument section (not shown) equipped with an indicating instrument.

Next, the thermocouple mounting structure in the microwave high temperature furnace according to the present invention will be described with reference to the embodiment shown in FIGS. 2 is a schematic diagram of a microwave high temperature furnace using the thermocouple mounting structure of the present invention, FIG. 3 is a diagram for explaining the thermocouple mounting structure in the microwave high temperature furnace of the present invention, and FIG. FIG. 4 is an enlarged view of FIG. 3.

The thermocouple mounting structure in the microwave high temperature furnace of this embodiment is a structure in which the above-mentioned protective tube type thermocouple 1 for microwave high temperature furnace is mounted in the microwave high temperature furnace 10 as shown in FIG. Specifically, the sensor unit 2 having a thermocouple, and the sensor unit 2 is covered in a hermetically sealed state, and has heat resistance capable of withstanding at least 1000 ° C.,
And a protective tube 3 formed of a microwave impermeable material that does not allow the transmission of microwaves, and a conductive portion 5 is formed at a base end side portion of the protective tube 3. This is a structure in which a protective tube type thermocouple to which a mounting member 6 for mounting in a microwave high temperature furnace is attached is attached to a microwave high temperature furnace 10.

The protective tube type thermocouple 1 for the microwave high temperature furnace is arranged such that the tip of the protective tube 3 is located near the object 20 to be measured, and the mounting member 6 is used to attach the protective tube type thermocouple 1 to the microwave high temperature furnace 10. It is attached to the housing 11. Hereinafter, the thermocouple mounting structure in the microwave high temperature furnace will be described in detail with reference to FIG. 3, but the protective tube type thermocouple 1 for the microwave high temperature furnace is as described above and will not be described.

Therefore, the overall structure of the microwave high temperature furnace 10 will be briefly described. The microwave high temperature furnace 10 includes a housing 11 and a baking chamber 1 provided in the housing 11.
3, microwave generation means 14, and a waveguide 15 that connects the housing 11 and the microwave generation means 14 to each other.

At least the inner surface of the housing 11 is made of a material capable of reflecting microwaves, for example, a stainless material.

Inside the housing 11, there is provided a firing chamber 13 defined by a heat insulating partition wall 12 made of a material capable of transmitting microwaves, such as foamed alumina. Inside the firing chamber 13, there is formed a ceramic molding for sintering. A body (measurement target) 20 and the like are placed.

The microwave generation means 14 is for outputting microwaves and is composed of a microwave oscillator. The frequency of the microwave output from the microwave oscillator is preferably 0.9 to 100 GHz, and more preferably, an inexpensive microwave oscillator can be used in 2.4.
It is 5 GHz.

The microwave output from the microwave generating means 14 is supplied to the microwave generating means 14 and the housing 11.
The inside of the housing 11 is irradiated with light through a waveguide 15 that communicates with the.

A spherical reflector 16 for dispersing the microwave is provided at the microwave incident portion in the housing 11.
When the microwave is radiated into the housing 11, the microwaves are dispersed by the reflector 16 and then are multiple-reflected by the inner surface of the housing 11 and transmitted through the heat insulating partition wall 12 to enter into the firing chamber 13. Is configured to.
The spherical reflector 1 for dispersing the microwave
Instead of 6, a microwave high temperature furnace configured to disperse microwaves by using rotary reflecting blades may be used.

The object to be measured 2 is placed in the housing 11.
A protective tube type thermocouple 1 for measuring a temperature such as 0 is attached. Specifically, as shown in FIG. 3, the protective tube type thermocouple 1 for a microwave high temperature furnace is arranged so that the tip of the protective tube 3 is located near the measurement target 20, and is attached to the mounting member 6. And is attached to the housing 11 of the microwave high temperature furnace 10.

More specifically, the protective tube 3 of the protective tube type thermocouple 1 for microwave high temperature furnace is provided in the protective tube insertion portion 17 provided in the housing 11 and the heat insulating partition wall 12 constituting the firing chamber 13. The protective tube insertion holes 12a are inserted through the protective tube insertion openings 12a, respectively, and the protective tube 3 is arranged so that the tip of the protective tube 3 is located near the measurement target 20, as shown in FIG.

The mounting member 6 provided on the conductive portion 5 at the base end side portion of the protective tube 3 is attached by engaging with the protective tube type thermocouple mounting member 18 provided outside the housing 11. . As a result, the protection tube type thermocouple 1 for the microwave high temperature furnace is arranged such that the tip side portion of the mounting member 6 is arranged inside the furnace and the base side portion of the mounting member 6 is located outside the furnace.
It is attached to the microwave high temperature furnace 10. Even if microwaves are irradiated in this state, the protection tube 3 does not transmit the microwaves and does not enter the protection tube 3, so that the microwaves may leak out of the furnace through the protection tube 3. Absent.
Further, since the conductive portion 5 is formed at the base end side portion of the protection tube 3, and the mounting member 6 for mounting on the housing 11 of the microwave high temperature furnace 10 is mounted on the conductive portion 5, The microwave transmitted on the surface of the protective tube 3 is not grounded and leaks out of the furnace.

[0037]

According to the inventions set forth in claims 1 and 2, the temperature of the object to be measured can be measured more accurately and extremely inexpensively without the microwave leaking out of the microwave high temperature furnace.

[Brief description of drawings]

FIG. 1 is a side view of an embodiment of a protective tube type thermocouple for a microwave high temperature furnace according to the present invention.

FIG. 2 is an overall schematic view of a microwave high temperature furnace using the thermocouple mounting structure of the present invention.

FIG. 3 is an enlarged view of an embodiment of a thermocouple mounting structure in the microwave high temperature furnace of the present invention.

FIG. 4 is an enlarged partial sectional view of the vicinity of the mounting member in FIG.

[Explanation of symbols]

1 Protective tube type thermocouple for microwave high temperature furnace 2 sensor 3 protection tube 4 terminal box 5 Conductive part 6 Mounting members 7 Fixing member 8 Conductive ring 10 microwave high temperature furnace 11 housing 12 Thermal insulation partition 12a Protection tube insertion port 13 firing room 14 Microwave generator 15 Waveguide 16 Spherical reflector 17 Protection tube insertion part 18 Protective tube type thermocouple mounting member 19 open / close door 20 measurement target 21 conductor

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor in Meng Steel             2-6, 6-10 Honmachi, Tajimi City, Gifu Prefecture             Sakae Electric Furnace Factory F term (reference) 2F056 BP07 CL13                 4K056 BB07 FA12

Claims (2)

[Claims] 1. A sensor part having a thermocouple, and covering the sensor part in a hermetically sealed state, and at least 100 parts.
A protective tube formed of a microwave impermeable material which has heat resistance capable of withstanding 0 ° C. and does not allow transmission of microwaves, and a conductive portion is formed at a base end side portion of the protective tube. A protective tube type thermocouple for a microwave high temperature furnace, characterized in that a mounting member for mounting on a housing of the microwave high temperature furnace is attached to the conductive portion. 2. A sensor unit having a thermocouple, and the sensor unit is covered in a hermetically sealed state, and at least 100
A protective tube having heat resistance capable of withstanding 0 ° C. and formed of a microwave impermeable material that does not allow transmission of microwaves, and a conductive portion is formed at a base end side portion of the protective tube. In the structure, a protective tube type thermocouple in which a mounting member for mounting in a microwave high temperature furnace is attached to the conductive portion has a structure attached to the microwave high temperature furnace, and the tip of the protection tube is A thermocouple mounting structure in a microwave high temperature furnace, wherein the thermocouple mounting structure is arranged so as to be located in the vicinity of a measurement target and is mounted to the housing of the microwave high temperature furnace by the mounting member.